Electrical Patch for Physiological Measurements

ABSTRACT

An electrical patch and associated system for acquisition of physiological data is described. The patch has a design that enables a variety of configurations depending upon the requirements physiological measurements to be made. Patches with single input channels to patches with multiple input channels, processing capabilities and radio communication can all use the same physical configuration. The design includes a battery management system to enable long term data acquisition and an optimization process that includes mirroring of algorithms on the patch and devices local to the user with algorithms running on a centrally located server. The server can then optimize data acquisition and analysis algorithms. The components of the system and methods of use are included.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional application 62/161,884, filed on 15 May 2015, titled “Electrical Patch for Biological Measurements”, and, U.S. Provisional Application 62/309,230, filed on 16 Mar. 2016, titled “Electrical Patch for Biological Measurements”, and, U.S. Provisional Application 62/309,300, filed 16 Mar. 2016 titled “Health Care Device with Battery Management System”, and, U.S. Provisional Application 62/311,300, filed on 21 Mar. 2016, titled Electrocardiogram Device and Methods”, all having at least one common inventor and all are currently pending.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a health care device for measuring, recording and analyzing a physiological property of a user and includes a battery management system and methods of use.

2. Related Background Art

As sensors for physiological data and data acquisition and data handling systems have improved and the amount of physiological data available to caregivers has expanded. It is now common practice to acquire data continuously from electronic sensors attached to patients. Examples of such sensors include temperature probes, probes sensitive to movement to detect breathing and posture, sensors that detect electrical signals from the patient such as electroencephalograms (EEG) and electrocardiograms (ECG), sensors for chemistry such as blood oxygen detectors and blood glucose levels. Sensors for detecting the location of the Patient, such as GPS receivers, and radio triangulation's data is typically acquired versus time. The signal from the sensors is often a voltage or current measurement that is passed through an analog to digital converter to provide a numeric intensity measurement versus time. The analyses look for variations or patterns in the acquired data that are indicative of a disease or abnormal state. In many cases, such as that in the case of electroencephalogram and electrocardiogram data, the data represents repeating waveform patterns. The analyses use filtering and transform techniques to extract waveform morphology, fundamental frequencies and patterns in the acquired data. The data may be acquired over periods of time from seconds to months. The sensors and data acquisition may be used for patients that are not moving, such as those confined to a bed and those in an intensive care unit of a hospital or the sensors may be attached to ambulatory patients and others, where data is collected continuously as they move about in their normal life routines. Athletes using sensors during fitness training is now common. There are a wide range of uses for the devices. In some cases, the devices are used for continuous monitoring in an intensive care situation where there is a risk of harm or death and immediate alarms are required. There are other cases where there is a need for diagnoses that might not be life threatening but still require continuous data collection. And there are cases where data may be collected intermittently. A common feature for all the situations however is that the sensors collecting the data must fit comfortably to the user and not inhibit movement by the wearer.

Current sensors still are lacking. They are generally too bulky for comfortable continuous wear and require a connection to an electronic device for storage of data and perhaps even a third device for communication and transmission of the data to a remote site for data analysis. Currently the electronic devices used for local storage are bulky and hinder free movement by the wearer. There is a need for a compact one-piece data acquisition device that can be worn comfortably by both ambulatory patients and others. There is a need for a device that does not require the user to continuously wear a secondary device for data collection and transmission to a remote site for data analysis. There is a need for a range of capabilities. There is a need for sensors that include electronics with memory and computation capabilities to give immediate feedback to a patient or caregiver, and locate the patients on a map, so that they can be reached quicker by the caregivers. There is a need for low cost sensors that have limited storage and computational where data may be collected and then downloaded for viewing and analysis off line. In some cases, the diagnoses call for data collected simultaneously from multiple sites on the user's body. There is a need for sensors that can be used as part of an array of sensors on the user. There is a need for sensors that can communicate data and/or data acquisition control signals amongst a plurality of sensors in use simultaneously.

A common feature of the data analysis for such physiological information is to look for anomalies that may indicated either a disease state or a critical state where a caregiver intervention is required to aid the patient. The latter are common in intensive care unit situations. The large amount of data being acquired from a large number of patients has required the development of automated routines to evaluate the collected data. Frequently the analysis is used to provide automated response, such as in the case of insulin dosing systems responsive to automated blood glucose measurements or in the case of pace makers where an external electrical stimulus is provided upon detection of irregularity in the patient's heartbeat. The physiological data analysis is also frequently used to trigger alarms indicating immediate action is required. There is a need for sensors that can be selected and integrated into the data analysis routines.

The extended measurement times and the use on ambulatory patients have necessitated the use of batteries to power these systems. The systems frequently consist of multiple devices such as a sensor on the patient, a wireless transmission device to send the sensor data to another recording and analysis device and a networked recording, analysis and transmission device for communication with the physician or other care giver. These devices may be mobile or stationary, but for ambulatory data there is a need that at least the sensor and a communication device that may or may not be incorporated with the sensor are battery operated. The critical nature of the data and the search for rarely occurring events requires continuous high reliability in the battery system. The battery system must be able to operate the sensors and communication devices for days at a time without interruption. In the specific example of an electrocardiogram, data is acquired over a period of days is typically referred to as a “Holter scan”. The data provides detailed information on the actual number of beats of each of several morphology types, number of abnormal beats, and exact length and type of arrhythmic episodes.

The current state of the art for battery power to health monitoring devices for an ambulatory patient is to have a separate battery in each of the diverse devices. The battery may be rechargeable or disposable and there may be circuitry to maintain operation for very short intervals required to change batteries. Frequently however data acquisition is interrupted if new batteries are required. If the patient is not convenient to a supply of batteries the service interruption can be extensive including loss of data, alarm and notification capabilities. With long term monitoring the loss of a significant data interval may require repeat testing. There is a need for improvements in the battery management system used with ambulatory health monitoring devices.

The discussions here will demonstrate designs and methods applied specifically to electrocardiogram data, but those skilled in the art will readily see the applicability to data acquisition any other similar timing varying physiological data.

The device being comfortable and unobtrusive for patients increases the likelihood that the patient will continuously wear the device, which contributes greatly to diagnostic yield.

There is a need for a patch that can be comfortably worn long term. Current patch designs used for ambulatory arrhythmia monitoring use wet gel electrodes with electrolytes in solution that can irritate the skin. A strong adhesive can irritate or damage skin when removed. The adhesive can break down, the patient can sweat, humid conditions and activity currently limits patch wear time to 2 to 10 days. When the patch does fall off, it generally cannot be replaced and monitoring is discontinued. It is advantageous to be able to move the patch, or replace the adhesive during the monitoring period.

DISCLOSURE OF THE INVENTION

The present invention provides a new design for an electronic patch for physiological measurements. Size is important to comfort and unobtrusive use. An internal rechargeable battery allows elimination of enclosures for a replaceable primary cell battery. In the rechargeable variation of the design, and second device containing a charging capability can fit over the patch and perhaps even be attached to the skin temporarily during recharging. The second device can charge through induction or wireless methods or be attached electrically. The second device can also contain local and wide area radios.

The communication device utilizes a cellular or WiFi radio for wide area communications with the server. It incorporates a local area radio or other communication means for bidirectional communication with the patch (this could be radio, near field communications, optical, direct connection, acoustic etc.) This results in dramatic power consumption reduction because the proximity of the two devices enables very low transmit power. The entire radio link could also be shielded from outside electromagnetic interference further improving the link budget thereby reducing or eliminating any re-transmission required due to bit errors in the link. In one embodiment the communication device is inductively charge a rechargeable battery placed in the sensor. A rechargeable battery allows for a completely sealed device, which has advantages with respect to size and ingress protection. The communication device has a means for recharging, and charging the patch. The communicator could be affixed to the body and worn over the patch to provide wide area communications from the patch while the patient is ambulatory. Otherwise, for patient comfort, the communicator can be placed once or twice a day to transmit all collected data to the server.

In some embodiments wide area communication is used so serious arrhythmic events can be detected and treatment can occur promptly. In many cases however, a patient at risk for these events will be hospitalized and not a candidate for ambulatory monitoring. Therefore, it is sometimes desirable to transmit data over the wide area network less frequently. Data can them be transmitted more power efficiently by decreasing connection/discovery/disconnection overhead incorporated into the radio protocols. The range could also be decreased by requiring a patient interaction (pressing a button) to transmit data, ensuring proximity of the two devices. The accelerometer could detect when a patient is lying down and look for a bedside communicator, ensuring range without patient interaction at the expense of perhaps more frequent discovery attempts. In another embodiment, the patch runs a local algorithm that detects only serious arrhythmias and provokes the patient to connect or the patch itself connects to the WAN automatically.

In one embodiment the patch design provides an electronic system that can be modified for different uses. In a first embodiment the patch contains a minimalist set of electronics including analog to digital converter, microprocessor and memory. In one embodiment the patch includes memory storage and the data transfer to a computing device is through physically attaching the patch electronics to the computing device. In one embodiment the transfer is through use of a memory card. In another embodiment the transfer is through removing patch electronics and attaching the electronics to the computing device. In another embodiment the patch is connected to the computing device using a wire connection such as a USB cable. In a second embodiment the patch further includes electronics for wireless transfer of data. In one embodiment the wireless electronics include an RF transceiver that is coupled with a like RF transceiver to a receiving device. In another embodiment the patch includes a multi-channel A/D and memory modules and RF transceivers that are interconnected through Direct Memory Access (DMA). The memory modules include both short term fast access memory and longer term storage. In one embodiment the RF electronics includes the ability for communication to a receiving device and for communication amongst multiple patches located on the user's body.

In one embodiment the receiving device is also a computation device and is programmed to provide analysis of the physiological data. In another embodiment the receiving computation device includes remote communication capabilities such as through the internet, through a local area network and/or through a cellular network, and can send and receive data and programming instructions to a central location remote from the user. In one embodiment the receiving computation device is a programmable cellular device such as a cell phone that includes computing capabilities. In another embodiment the receiving computation device is located remote from the user. In a preferred embodiment there is a receiving computing device local to the user and a second computing device located remote from the user that may be accessed by a caregiver for the user. In a preferred embodiment the patch acquires heart data in the form of a multi-lead electrocardiogram (ECG) and the receiving device analyzes the received data for irregularities in the user's electrocardiogram. The caregiver may be a medical professional such as a doctor, nurse, ECG technician, etc.

In another embodiment the patch includes computation capabilities that provide a first analysis that is then used in algorithms to control the data acquisition process.

In another embodiment there is a computation device local to the user and a remote computation device that is local to a caregiver and the device local to the user uses an analysis algorithm that is a “mirror” of the algorithm on the remote computation device. The remote computation device may include an array of algorithms and a decision algorithm that selects the most appropriate algorithm for the particular patient or the particular condition of that patient. The remote computation device then sends the selected algorithm to the device that is local to the patient, thereby reprogramming the local device to use the selected algorithm for analysis.

Frequently for ECG data it is important to acquire data from a patient/user continuously over a long period of time. Battery life and management of the power system is critical to successful data collection from an ambulatory user. In one embodiment the present invention solves the challenges issues with battery life in an ambulatory health care monitoring device by having a pair of interchangeable batteries within two devices local to the patient. Typical embodiments of health care devices include a portable device including sensors attached to the patient and a communication and/or computation device that may or may not be portable. There are generally size constraints on the device with the attaching sensors as the patient must wear this device even while active. A secondary communication device may not have such size constraints especially if the secondary communication device is a central communication station that only intermittently must communicate with the worn device. In one embodiment of the invention the size constrained device includes a battery that is interchangeable with a spare battery contained in the secondary device

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows prior art hardware.

FIG. 2A shows a first embodiment for hardware of the invention.

FIG. 2B shows details of a patch embodiment used in FIG. 1.

FIG. 3 shows various positions on a user for a single patch.

FIG. 4 shows various positions for multiple patches on a user.

FIG. 5A is a side view cross-section showing components of an embodiment of the patch.

FIG. 5B is a side view cross-section showing components of another embodiment of the patch.

FIG. 6A is a bottom view block diagram of an embodiment of the hardware components of the patch.

FIG. 6B is a bottom view block diagram of another embodiment of the hardware components of the patch.

FIG. 7 is a block diagram of a minimalist version of the electronics of the patch.

FIG. 8 is a block diagram of the electronics of the patch having a second level of capabilities.

FIG. 9 is a block diagram of the electronics of a patch having approximately 2 days of data memory.

FIG. 10 is a block diagram of the electronics of a patch having approximately 30 days of data memory.

FIG. 11 is a block diagram of the electronics of a patch having multiple options for data and programming memory storage.

FIG. 12 is a block diagram of a physiological data acquisition device using new electronics including an invented battery management system.

FIG. 13 is a block diagram of another embodiment of a physiological data acquisition device using new electronics including an invented battery management system.

FIG. 14 is a block diagram of a physiological data acquisition device using new electronics including an invented battery management system.

FIG. 15 is a block diagram circuit diagram for the devices of FIGS. 12-14.

FIG. 16 is a flow chart for use of the battery management system of FIGS. 12-15.

FIG. 17 is a flow chart of the algorithm management system for the patch design.

MODES FOR CARRYING OUT THE INVENTION

Referring to FIG. 1 in prior art, a monitoring sensor 102 is attached to a patient 101. The Monitoring sensor includes sensors 104 attached to the patient. The sensor device 102 is in communication with a secondary device 103. The secondary device includes input and output means such as buttons 106 for inputting information and triggering events and means for viewing status 105. Non-limiting examples of sensors included in the sensor device 102 are voltage sensors for detecting electrocardiogram and electroencephalogram and respiration information, optical sensors to measure for example blood oxygen content optically, and chemical sensors to measure pH or blood glucose, potentiometric sensors to measure blood chemistry, thermal couples and thermal resistors to measure temperature and accelerometers and strain gauges to measure movement and respiration. The data from the sensors 104 is collected in a worn device 102 and transmitted to a secondary device 103. The data may be transmitted between the devices 102, 103 via wired or wireless communication. The communication may be over a local network or a global network, by blue tooth and other local and global communication means known in the art. The devices 102, 103 may further include computation capabilities that are programmed to acquire and analyze the data. The devices 102, 103 may further include communication means to communicate physiological data or the analysis results of physiological data to a central processor (not shown) where a care-giver may further view and analyze the data. The care-giver may be local to the patient or remote. The communication between the devices 102, 103 and the central processor may be through a wired communication link, a wireless communication link, a cellular communication link, a blue tooth communication link or any of the many means known in the art for data communication.

The Patch

As shown in FIG. 2A, the present invention, by contrast, includes an electrical patch 202 attached to a human subject 201. The patch 202 includes electrodes and data acquisition and storage electronics to acquire physiological data from the patient 201. As shown the patch is configured to acquire electrocardiogram data, skin temperature, and the patient's posture. Other configurations are possible, non-limiting examples of which include voltage sensors for detecting electrocardiogram and electroencephalogram information, optical sensors to measure for example blood oxygen content optically, and chemical sensors to measure pH or blood glucose, potentiometric sensors to measure blood chemistry, thermal couples and thermal resistors to measure temperature and accelerometers and strain gauges to measure movement and respiration. In one embodiment, physiological data is acquired and stored by the patch and then transferred to a communication device 203. The communication device 203 is an electronic device that transfers data received from the patch 202 to another computing device also attached to a communication device. The computing device may be local to the user 201 or may located remotely. If located remotely data may be transferred from the communication device 203 to the remote computing device by wired or wireless means.

Data is transferred from the patch to the communication device 203. The recorded data can be transferred to the communication device/receiving station by several means:

In one embodiment, the patch is physically sent in to the location of the Receiving Station, which can be equipped with an optional USB cradle 206. The patch is placed in the cradle 206, which makes contact to the electrodes of the patch 202. An electromagnet in the cradle, is sensed by a magnetic switch in the patch. The patch will then switch the function of its electrodes to act as an SPI port. Data is downloaded from the patch through the SPI Port/electrodes, to the cradle 206, which then interfaces the SPI port to the USB port of the cradle 206, and transfers the data through the USB port to the receiving station 203.

The SPI Port can also be used to activate a self-testing and diagnosis of the patch, as well as update the firmware of the patch.

In another embodiment, the patch 202 will contain an RF transceiver, which will communicate to a hand held device 203, which is normally plugged into a power outlet through a wall-plug adaptor 207, allowing its batteries to be charged while operating. Embodiments of the hand held device 203 include means to communicate to the patch such means include RF Devices, such as Bluetooth, Low Power Blue Tooth, or a custom built proprietary transceiver.

The hand held device 203 communicates to a separate receiving station/remote computing device 215 either directly through the cellular network, or by attaching to Wi-Fi network at the user's/patient's location. In another embodiment the hand held device 203 is a programmable cellular telephone.

In one embodiment, the hand held device 203 is placed near the patient's bed, and data recorded during the day by the patch, is transferred through the hand held device to a remote computation device/receiving station 215, every night while the patient sleeps.

In another embodiment data is transferred by moving the hand held device 203 close to the Patient for several hours a day.

The battery condition of the patch 202 and communication device 203 is transmitted to the Receiving Station 215, allowing the monitoring center location of the receiving station 215 to inform the Patient 201 if the Patch's Battery needs to be replaced.

The communication may also be through a direct physical link such as a wired link between a port (not shown) on the patch 202 and the communication device 203. The communication may be through removal of a memory device from the patch 202 and insertion of the memory device in a slot 206 on the communication device. The communication may also be through a physical connection on the patch 202 such that the patch itself is plugged into a slot 206 on the communication device. Communication may also be through remove of a portion of the electronics on the patch 202 and physically connecting the removed electronics to the communication device. In another embodiment the patch is used without a communication device 203. In one embodiment the patch is prescribed by a caregiver and delivered to a user and then attached to the user. After a preselected span of time the patch is removed and returned to the caregiver ho downloads data from the patch either to a communication device similar to that shown in FIG. 2 or the data may be downloaded directly from the patch 202 to a computing device 215. The communication to the computing device may be the same as any of the modes described for communication to the communication device 203.

The communication device 203 includes a user interface 204. The user interface can be used to trigger the communication device to send a signal to a remote location as well as to control data acquisition local to the user 201 through the patch. The communication device may include computation electronics programmed for analysis of the electrical signal received from the patch 202. In another embodiment the computation electronics are included in the electronics of the patch itself. The communication device also includes a connection 207 to a power supply. The connection 207 is shown as an electrical plug, but other power supplies may be used instead such as a battery power supply and solar panel, both, either incorporated in the communication device 203 or attached to the communication device. More details of the patch are shown in FIG. 2B. The bottom view 208 shows an electronics module 212 and three electrodes 210. The electrodes are connected by wires 211 to the electronics module. In practice the configuration may include more or fewer electrodes although two electrodes are required to provide a voltage measurement versus some reference. Any of the three electrodes may be used as a reference electrode for voltage measurements to be made by the other two. The electronics module 212 may be permanently attached to the patch or may be removable. In one embodiment a memory device (not shown) may be inserted into the electronics module 212 for data collection and then removed for downloading to a computation device. In one embodiment the electronics module is a circuit board that further includes articulated wings 215 (shown here for only one wing in dashed lines) that extend towards each of the electrodes 210 and enable direct connection of the electrodes 210 to the circuit board through spring loaded connectors (seen in FIG. 5A below). Other configurations of the electronics module are shown in later figures. In one embodiment the electronics module may be swapped to change the functionality of the patch. In a preferred embodiment the bottom of the patch is shielded with a breathable material such that only the electrodes are exposed for attachment to the user. The electrodes may be made of a variety of materials. In one embodiment the electrodes are made of conductive materials. Ag/AgCl electrodes are common in prior art but known to cause irritation after long term use. Conductive metals are often commonly used. In some cases, the metal electrodes require a conductive gel applied to ensure continuous contact. In a preferred embodiment the electrodes are dry electrodes. In one embodiment an electrode made of material selected from: titanium, stainless steel, and platinum is used. In another embodiment metallic electrodes are used with a deposit of TiN on the surface. In other embodiments the electrodes are composed of a polymer substrate, such as polycarbonate upon which a conductive coating. In one embodiment TiN is sputter coated onto the electrode base. The base may be a metallic electrode or a polymer base and the sputtered TiN makes the base conductive for measurements. In another embodiment the electrodes are non-contact capacitive electrodes. In another embodiment the adhesive layer is “pre-soaked” with electrolyte gel around the holes for the metal electrodes.

The top of the patch is shown in the second view 209 the top 214 is a flexible material chosen to protect the electrodes and electronics of the patch and chosen such that it may be firmly, but comfortably attached to the body of the user. In the preferred embodiment the top cover includes a porous fabric cover such as one made from porous polyfluorinated hydrocarbon materials such as those sold as GoreTex® (Gore-Tex is a registered trademark of W.L. Gore & Associates), polymer coated cloth, or porous polyethylene, woven polyesters and polyester-polyurethane copolymers such as spandex. The patch may further include adhesive strips attached to the bottom side of the porous fabric for adhesion to the user. In another embodiment, the patch further includes wound dressing or biocompatible adhesive incorporated into the bottom side of the porous cover. Nonlimiting examples of the wound dressing adhesive include 2-octyl cyanoacrylate and other cyanoacrylates such as n-butyl-2 cyanoacrylates). Other dressing adhesive materials include films, gels, foams, hydrocolloids, alginates, hydrogels and polysaccharide pastes, granules and beads as are known in the art. The combination of the solid dry electrodes such as electrodes including a TiN deposit on their surface along with use of the wound dressing adhesives has been found to provide a patch that may be worn continuously for 30 days and longer. In another embodiment the housing includes multiple articulated arms 213 with separate circuit boards connected by flexible connectors. The articulated arms 213 allow conformance of the patch to the user's body.

The Patch may be worn in any position a preferred four positions 301-304 are shown in FIG. 3. The differing orientation allow for measurements of multiple ECG vectors. In one embodiment The ECG Vectors are sensed automatically by a version of the Patch that includes a built-in Accelerometer. In another embodiment the communication device is paired with the patch and the pairing process includes entering the position and orientation of the patch. The patch is also not limited to wearing a single patch at a time. FIG. 4 shows a user wearing a plurality of patches 401. In one embodiment the patches include an accelerometer that automatically determines the orientation of each of the patches. In another embodiment the patches include rf communication not only between each patch and the communication device shown in FIG. 2, but can also communicate from one patch to the other such that an event detected on one patch can be synchronized with the detection on a second patch. In one embodiment the patches may be activated such that an event on one patch can trigger a change in the data acquisition parameters on a second patch. In another embodiment each of the patches are independently paired with the communication device and the pairing includes detecting the orientation of each of the patches and further includes entering the location of each of the patches.

FIGS. 5A and 5B show two configurations of the patch in cross-sectional views. Referring to FIG. 5A, in one embodiment the patch is assembled into a clamshell plastic case comprised of a top half 501 and a bottom half 506. In the preferred embodiment the clamshell is made from an acrylonitrile butadiene styrene (ABS) polymer. The electrodes 504 along with a ground contact (not shown), will be molded into the bottom half of the case. In a preferred embodiment, the ground contact will be recessed from the outside of the case, and can only be contacted using a pogo-pin in the USB Cradle. In another embodiment an integrated rechargeable battery is used and the patch is conformally coated to the circuit board directly without an exterior top housing. Thereby making a very thin patch for comfort and unobtrusiveness. In another embodiment a portion of the patch is conformally coated and only one of the arms containing an electrode is left uncoated to include a battery housing on the side opposite the electrode.

The circuit board 502 sits on the inside of the bottom half 506 of the case, and makes contact to the electrodes 504 and the ground contact using springs 505 mounted at the bottom of the circuit board 502. In one embodiment, the circuit board is fastened to the bottom half of the case 506 using small screws, which will go through the circuit board 502, and screw into holes in each electrode 504.

The components on the circuit board 502 may include the power supply, processor, memory, accelerometer, thermistor, a giant magnetoresistance (GMR) sensor, and an RF communication chip. The battery 514 sits on top of the circuit board 502. In the preferred embodiment the battery is removable and located at center of the upper clamshell 501 to provide maximum room for a battery to include operation time between charging or replacing the battery. ECG Circuits are laid out on the top and bottom of wings of the PCB that extend towards each of the electrodes. The wings may be seen seen in FIG. 2B. The antenna (not shown) for the RF chip, will be built on a separate rigid or flex printed circuit board, which will be installed over the wings of the circuit board 502 in the top half 501 of the case.

In one embodiment the two case halves 501, 506 will be either glued together, or ultrasonically welded to each other, to provide a water-proof seal. The embodiment will further include a cavity in the housing for a battery tray to plug into the device (not shown). In one embodiment the entrance to the battery tray compartment is protected using a hydrophobic sheet of material that will enable access for changing the batteries while still protecting the interior from moisture.

In one embodiment, shown in FIG. 5A, the electronics of the patch are on a circuit board 502 and the electrodes 504 are connected to the board through connectors 505 such that the electronics may be removed from the user while the electrodes 504 remain connected and in contact with the user. The Patch is connected to the user using a layer of adhesive on a breathable flexible base material 503. In the preferred embodiment the adhesive layer on the underside of a foam 503 liner. In one embodiment the foam liner 503 includes a wound dressing adhesive. The housing for the patch is a clam shell design having a top portion 501 and a bottom portion 506 that are connected together using an interface 507. In one embodiment, the top portion 501 of the case comes in different sizes to accommodate different size batteries. This changes the thickness of the top half of the case depending on the battery needed for each configuration of the device, but leaves the bottom half 506 of the case the same for all versions of the device. In one embodiment the electronics 502 are attached to the top portion 501 of the shell such that the top portion 501 can be removed from the bottom portion 506 that remains connected to the patient/user. The top portion and the electronics can be connected to a docking station (not shown, but see 203 FIG. 2A) for data download and recharging the battery. In one embodiment a pair of top portions are used during data acquisition such that one of the pair is connected to the user for data acquisition and the other of the pair is docked for recharging and data transfer. In another embodiment the electronics remain connected to the bottom portion of the clam shell and the top portion includes the battery such that the battery can be swapped by swapping the top portion 501 of the clam shell. In this embodiment a pair of top shells are used in unison by swapping for maintaining power to the electronics through the battery management system discussed below. In one embodiment the electronics 502 further include an alert mechanism to tell the user the battery power is low and the batteries should be swapped. The alert mechanism can include an LED, vibrator or other systems known in the art to alert a user of an electronics device of some event. In another configuration of the patch, shown in FIG. 5B, the patch electronics are encased in a flexible cover 510. The electronics 502 are embedded or potted in a matrix 512 to protect from the environment. In one embodiment the electronics 502 are connected to the electrodes 504 via wire connectors. In another embodiment the electrodes are directly connected as shown in FIG. 5A. In a preferred embodiment the circuit board 502 includes flex points 517 thereby forming articulated arms 518 to which the electrodes 504 are attached. Patch designs may use combinations of the features from FIGS. 5A and 5B. As an example, the clam shell of FIG. 5A may be further covered with a flexible cover 510 as shown in FIG. 5B. In another embodiment the clam shell design of FIG. 5A may use wire connector to the electrodes as shown in FIG. 5B. Continuing with the design of FIG. 5B, the electrodes 504 are connected to a base 509. In one embodiment the base 509 is a flexible base. The base 509 is adhered to the user using a layer of adhesive 508. In the preferred embodiment the adhesive is a surgical wound adhesive as described above. In another embodiment, the electronics 502, potting 512 and cover 510 include a means to access a battery to power the patch such that the battery may be swapped. In another embodiment the patch includes a pair of batteries to maintain continuous power such that as one battery is being swapped the second battery maintains power to the electronics. Details of the battery management system are discussed below. In the preferred the patch's thickness 513 will be in the range of 8 to 12 millimeters.

In a preferred embodiment the bottom of the patch is shielded with a breathable and compressible material 503 such that only the electrodes' 504 tips are exposed for attachment to the user. The electrodes may be made of a variety of materials. In one embodiment the electrodes are made of conductive materials. Ag/AgCl electrodes are common in prior art but known to cause irritation after long term use. Conductive metals are often commonly used. In some cases, the metal electrodes require a conductive gel applied to ensure continuous contact. In a preferred embodiment the electrodes are dry electrodes. In one embodiment an electrode made of material selected from: titanium, stainless steel, and platinum is used. In another embodiment metallic electrodes are used with a deposit of TiN on the surface. In other embodiments the electrodes are composed of a polymer substrate, such as polycarbonate upon which a conductive coating. In one embodiment TiN is sputter coated onto the electrode base. The base may be a metallic electrode or a polymer base and the sputtered TiN makes the base conductive for measurements. In another embodiment the electrodes are non-contact capacitive electrodes. In another embodiment the adhesive layer is “pre-soaked” with electrolyte gel around the holes for the metal electrodes.

The width 515 of the compressible breathable material 503 is adjusted relative to the gap 516 between the bottom of the compressible material 503 and the bottom of the electrode 504 to control the pressure that is exerted pressing the bottom of the electrode against the skin of the user to maintain good contact. That is if the gap 516 is large relative to the thickness 515 more pressure is exerted in the contact of the electrode to the user when the base material 503 is adhesively attached to the user. IN one embodiment the base material is interchangeable with base materials of different thicknesses 515 and the proper thickness is selected based upon optimizing the strength of the signal measured from the electrodes 504 and the comfort of the user.

FIGS. 6A and 6B show additional views and embodiments of the patch design. In FIG. 6A the patch 601 is seen to be comprised of a set of electrodes 602 that are connected to a central circuit board 604 by wires 603. The patch further includes an input/output (I/O) port 605 and a battery 606. In one embodiment the circuit board 604 includes an A/D circuit for acquiring voltage data from the electrodes 602 a microprocessor and memory to store data. The microprocessor is programmed to control the A/D to acquire and store data in memory. The microprocessor is further programmed to transmit the data to a remote processor through the I/O port. In one embodiment the I/O port is a Universal serial bus (USB) port. In another embodiment the I/O port is a radio frequency (RF) communication port. In one embodiment the RF port may be used to communicate to a local storage and data handler device as described in FIG. 2B. In another embodiment the RF port may be used to send and receive signals from a second patch similarly equipped on the same user. The microprocessor may be further programmed to analyze the data acquired by the electrodes and signal the user to whom the patch is attached a result from that analysis. In another embodiment the I/O port receives data and programming instructions from a remote device. The Patch may further include a user interface 607. In one embodiment the user interface includes a means to signal the user based on a condition detected by the microprocessor. The condition may include battery level and the signal includes an instruction to replace the battery. The condition may further be related to analysis results indicating a physiological condition as determined by programming of the microprocessor to analyze data acquired through the electrodes. The user interface 607 may further include means such as a button for the user to whom the patch is attached to send a signal to the microprocessor. The signal may initiate data acquisition. The user interface may include both a means to alert the user, such as light, buzzer or LCD or similar screen and a means for the user to input to the microprocessor. Input means can include a button or plurality of buttons. In one embodiment an accelerometer (discussed below) included in the patch is further used as the user interface such that if the user taps the patch, the accelerometer detects the motions and the microprocessor is programmed to take an action based upon that detection. In another embodiment another embodiment the microprocessor is programmed to take different actions based upon the number of taps detected in a given time period. In another embodiment the microprocessor is programmed to take a pre-selected action based upon the type of motion detected. In one embodiment if the motion detected by the accelerometer indicates the user has fallen the microprocessor may be programmed to send a signal through the I/O port to an external device to signal for help.

The patch electronics 604 can include a thermal sensing device (not shown) such as a thermocouple or thermistor for monitoring the skin temperature of the user. The temperature information is recorded periodically, and transmitted with the ECG data detected by the electrodes 602.

The patch electronics 604 can further include an accelerometer. Data from the accelerometer is recorded periodically, and transmitted to the receiving station (see FIG. 2B) along with the user's/patient's ECG. The data from the accelerometer, can indicate the position of the user (sleeping, walking, sitting, etc.) throughout the day. It can also inform the receiving station of any unusual events, such as the patient falling (Syncope), or running into objects, etc.

The accelerometer can also be used as a patient input device 607 for patient activation of events or to record markers. This can be done for instance by the patient double tapping the patch when they feel a symptom.

Each version of the patch will have enough memory to store ECG and data from other sensors, for as long as its battery 606 would last. In one embodiment lossless compression is used for storing and retrieving the ECG and data acquired by the other sensors.

The electronic configuration of the patch can be tailored to the physiological data acquisition need. In some cases, a minimal system is required for short term data acquisition and transferring the data from the patch to a computation device located either locally to the user or remotely, by a physical contact between the patch and the receiving device. Such physical contact includes plugging the patch into a USB port or moving a memory card from the patch to a computing device. In other cases, the data acquisition requirement is for long term data acquisition, such as continuous data acquisition for days or weeks at a time with both storage and analysis located directly on the patch device and wired or wireless transfer of the data on the patch to either a local computation device or a remote computation device. A range of patch configurations to handle such needs and others in between is shown in FIGS. 7-11. The features of the embodiments shown in the FIGS. 7-11 may be cumulative. That is, for example the embodiment of FIG. 8 may include all of the features described on conjunction with FIG. 7 plus additional features. Features described in other Figures of the application may also be included or combined with the features of the devices in FIGS. 7-11. As an example previous Figures described the inclusion of temperature sensors and accelerometers. These devices can also be included with the features described in FIGS. 7-11. As such, the discussion of each of FIGS. 7-11 should take into account the features described in the all other Figures in this application. And the features in all other Figures may include the features included in FIGS. 7-11.

Referring to FIG. 7, a first embodiment of the patch components is shown. The version is intended for a single channel data acquisition. In one embodiment the single channel is multiplexed such that the signal is from the three electrodes in the patch as described above. The single channel can also include data acquisition for temperature sensing devices an and accelerometer. The patch is comprised of an input 701 for connection to an electrode to be attached to the user's body. The input includes an A/D converter. The input is connected to a microprocessor 702 that controls the data acquisition and storage. The acquired data is stored in memory 703. In one embodiment the memory is NAND memory permanently installed in the patch. The acquired data is transferred to a communication device or processor for analysis by placing the patch in a cradle that results in an electronic connection to the patch and the data is downloaded to an intermediate communication device that transfers the data to a centrally located processor for analysis. In another embodiment the patch is connected directly to a computing device and the data is downloaded directly to the computing device with no intermediate communication device. In a preferred embodiment the connection to the patch is made through a USB port. In another embodiment, the memory 703 is a memory card that may be removed from the patch after data acquisition and inserted into an interface slot common to computing devices for download, display and analysis of the acquired data. In another embodiment the patch the electrode attached to the patch through the interface 701 can be used for download of data by connection of the electrode to a computer interface and activation of the download by the microprocessor 702. The patch further includes a battery 705 to supply power to the microprocessor and interface a required and a power supply/regulator 704. In a preferred embodiment the battery 705 is rechargeable and is recharged when the patch is attached to either a computing device or communication device for data download. In another embodiment the battery is replaceable. In one embodiment installation of the battery triggers the start of the data acquisition. The microprocessor 702 is programmed to control the data acquisition process including the input parameters such as gain and noise filters in the input channel 701, manipulate the data such that it is in a preferred format and storage of the data on the storage device 703. The microprocessor may also include programming for all data acquisition devices included in the patch with appropriate gain, filter and sampling rates. For example, the signal form an ECG electrode may be sampled at a rate of 100 to 200 samples per second whereas the microprocessor may acquire data from an accelerometer at a different rate and acquire data from a thermal sensor from at still another unique sampling rate. In one embodiment the microprocessor is further programmed to monitor the battery status and insure data is not lost even if the battery is depleted. The microprocessor may be programmed uniquely for each user.

In another embodiment shown in FIG. 8, the patch may be configured for data acquisition and streaming of acquired data to either a communication device or directly to a computing device or both. The physical appearance of the patch may be the same as for the configuration discussed in FIG. 7 and only the electronics module is swapped for the components shown in FIG. 8. The configuration is comprised of a single channel input 801, a microprocessor 802 a radio 803, and battery 805 and power supply/regulator 804. In a preferred embodiment the microprocessor is serial peripheral interface (SPI) NAND capable. The radio may be any radio frequency communication device such as blue tooth or proprietary transceiver that is paired with a similar device on a communication device or computing device. In one embodiment the pairing may be between two or more of other patches. The radio device may be used for transferring acquired data from the input channel 801 to a computing device or a communication device. The radio may also be used for communication of the status of the data acquisition, communicating status of the battery 805, communicating the status of the connection to the electrode attached to the user. The communicating the status of the electrode may include a warning that the electrode is not effectively attached to the user. Where effective attachment is based upon the strength and quality of the detected electrical signal. In one embodiment the signal to noise of the acquired signal is compared to a preselected level and if the signal to noise is less than the preselected level a signal is sent through the radio 803 to inform a user or caregiver for a user that the patch needs to be better positioned. The radio 803 may also be used for receiving control signals from an external source. The control signals maybe for starting data acquisition, stopping data acquisition, setting parameters for the data acquisition process including filter setting, acquisition frequency, and processing parameters. The radio 803 may also receive programming commands for the microprocessor. In one embodiment the microprocessor is programmed to perform analysis on the incoming data and a signal is sent by the microprocessor through the radio to inform the user or the user's caregiver of the health status of the user based upon the physiological data acquired through the incoming channel 801. In one embodiment multiple devices may be connected to the input channel 901 and multiplexed and controlled by the microprocessor to sample the devices in turn, perhaps at different sampling rates. In one embodiment the microprocessor is programmed to change the sampling rate on one of the connected devices based upon comparison of the signal received from a different device. In one embodiment the different devices are one separate patches.

Referring now to FIG. 9 a system with additional electronic features and capabilities is shown. The configuration shown here is for a single channel device that includes limited memory. As shown in the Figure one embodiment includes memory limited to acquire data from the user for 1 or 2 days at the programmed sampling rate. As in the previous figures the device configuration includes an input channel 901 for acquiring data from measurement devices included in the patch. Measurement devices may be the three or more electrodes shown on the patches in previous Figures for ECG measurements, as well as thermocouples or thermistors, accelerometers, a magnetoresistance (GMR) sensor, and electrodes for other measurements including EEGs. The input channel 901 is connected to a microprocessor 902. In the preferred embodiment the microprocessor is Parallel NAND capable. The configuration further includes a SPI NAND memory. In one embodiment the memory 903 includes enough capacity for 1 or 2 days of data acquisition at a pre-selected sampling rate. The configuration further includes an RF communication module 904 such as a near field communication module or radio communication model such as that sold by Bluetooth corporation. The configurations further include a transceiver 906, such as those sold by Nordic Semiconductor. The configuration also includes a Balun Antenna 905. Power is supplied by a battery 908 and a power supply/regulator 907. The configuration enables transfers both to and from the patch by both wired, through connectors to the input 901 and through the RF module and the transceiver. The antenna 905 extends the range of the wireless communication such that the user/patient may wear the patch and either continuously or at preselected intervals transfer data to either an intermediate communication device or to a computing device. The SPI NAND memory module may also be used to transfer data if the device is configured as a removable memory card. In another embodiment the SPI NAND includes a connector port such that data may be transferred by a wired connection to an intermediate communication device or to a computing device.

Another configuration is shown in FIG. 10. This configuration includes all the features of FIG. 9: a single channel input port 1001, a microprocessor 1002, memory 1003, the RF module 1004, the antenna 1005, the transceiver 1006, power supply/regulator 1007 and battery 1008. A difference between this configuration and that of FIG. 9 is that this configuration includes memory that would be sufficient for 30 days of data acquisition. Other features, although nominally the same, would also be modified to manage 30 days of continuous data acquisition. Non-limiting examples include more processing capabilities in the microprocessor such that during the 30-day data acquisition period the device may provide updates and alarms based upon local, on the patch, analysis of the acquired data.

The processor may be further programmed to manage the battery power supply and send signals through the RF Module or the transceiver as to when the battery 1008 needs to be changed or recharged. The RF module or the transceiver may be sued to stream the data to a remote computing device for analysis of the acquired data and they may further be used to receive data acquisition and programming instructions. In one embodiment analysis programs on the patch are “mirrored” such that the remote computing device can perform identical data analysis as is done locally. In one embodiment the remote computing device can transfer new analysis programs to the patch of FIG. 10 thereby changing the mirrored analysis programs on the fly during data acquisition.

FIG. 11 shows a configuration with additional features to those shown in FIGS. 7-10. The input 1101 includes multiple channels 1-N. Direct memory access (DMA) 1102 is used for the connection to the microprocessor 1103. DMA enables continuous data acquisition without microprocessor intervention thereby allowing multitasking such as analysis algorithms to run on the microprocessor while data is simultaneously being acquired from the input channels 1101. Similarly, there is a DMA connection to the memory module 1104. The memory module may include one or a combination of the memory types, including SPI NAND 1105, parallel NAND 1106, ferroelectric random access memory (FRAM) 1107, and static random access memory (SRAM) 1107. The size or amount of memory is selected for the intended purpose. Patch designs can be used for both short term, less than a day, to long term, greater than 30 days, data acquisition and storage. The data may be transferred from the on board memory 1104 either by physically removing a memory device from the patch and inserting it into a computing device or intermediate communication device, or through a wired connection between the patch and the computing device or intermediate communication device or through wireless transfer. For wireless communication the patch further includes an RF module 1113. The components of the RF module may be any of those already discussed. In the example shown a transceiver 1110 with a Balun Antenna 1109 is used. The transceiver would be paired with a transceiver on a computing device or intermediate communication device for transfer of data from the patch and for communication to the patch. Communication to the patch includes programming instructions, data acquisition parameters, alerts regarding battery level, etc. In one embodiment the patch further includes an alert device, such as a light or vibrator, to instruct the user to change the battery or otherwise service the patch. The patch includes a battery 1112 connected through a power supply/regulator 1111 to provide power to the electronics.

Battery Management

Referring now to FIG. 12 a first embodiment of the battery management aspect of the invention showing details of the devices 202 and 203 of FIG. 2. The patch 1201 is worn by the patient for physiological data acquisition and the secondary device 1202 is in the locality of the patient. In one embodiment, the patch 1201 further includes batteries 1207, 1208 to power the device. In one embodiment a first battery 1207 is used to power the device through normal operation and the second battery 1208 is used to power the device when the first battery 1207 is depleted. The device further includes a power management circuit 1206. The circuit 1206 includes input devices such as analog to digital converters that measure the state of charge of the batteries 1207, 1208 and switches that connect a battery to the other devices 1203, 1204, 1205, 1211 that require power to operate. In one embodiment the power management circuit 1206 further includes a processor that may be programmed to route power from either the first battery 1207 or the second battery 1208. The program switches between the first battery and the second battery when the state of charge of the first battery falls below a pre-selected level and the state of charge of the second battery is above a pre-selected level. In another embodiment the user is notified through the input/output device 1205 when the source of power is switched from the first battery to the second battery indicating to the user that the device is now on “reserve” power as only a single battery has sufficient power to operate the patch 1201. The device further includes a connector 1209 that may optionally be connected to an external power source 1210. Non-limiting exemplary external power sources include an electrical outlet plug, and a USB connector that can provide power and a third battery external to the patch 1201. In one embodiment the power management circuit 1206 is programmed to switch between the external power source 1210 connected through connector 1209, the first battery 1207 and the second battery 1208 based upon the state of charge of the first battery, the second battery and pre-selected parameters. In another embodiment the batteries 1207, 1208 are removable and may be swapped with a fully charged battery. In one embodiment the second device 1202 includes a battery 1217 that may be swapped with one of the batteries 1207, 1208 or both. In another embodiment the power management circuit 1206 indicates to the user through the I/O device 1205 that the user should swap a battery 1207, 1208 with the second battery 1217. In another embodiment the programmed control of the power management circuit is included in the processor 1204 rather than in a second processor included in the power management device 1206 itself.

The second device 1202 is for acquiring physiological data from the first device and evaluating or otherwise processing the physiological data and/or transmitting that data elsewhere as to a centralized facility remote from the patient and the devices 1201, 1202. The second device 1202 is comprised of communication port 1212 that is in communication 1219 with the patch 1201. The communication 1219, as already discussed, may be by wired or wireless means as are known in the art. The communication port also provides a means of communication to a remote or centralized facility 1221. The communication path 1220 to the remote facility may be by wired or wireless means such as through a local network, a global network either of which may be connected to the internet. The communication may also be through a local wireless network such as Bluetooth technology (Bluetooth is a registered trademark of BLUETOOTH SIG, INC.) or through a global wireless communication network such as a cellular network. The device 1202 is further comprised of a processor 1213 that is programmed to control all the functionality described herein and ascribed to the second device. The processor is connected to a power control circuit 1215 that in turn is connected through a port 1216 to an external power supply 1218, a first battery 1214 and a second battery 1217. The second battery is interchangeable with the second battery 1208 of the patch 1201. The power control circuit controls the distribution of power to the operational devices of the second unit and to supply power to a first battery 1214 when the unit is connected to an external supply 1218 and from the first battery 1214 when the unit is not connected to an external supply. The power control circuit also supplies power to the second battery 1217 which may be charged from power supplied either by an external power supply 1218 or from the first battery 1214. The device 1202 further includes an input/output means 1222 to communicate to the user and to accept input as required form the user. One communication of the i/o device 1222 is the state of charge of the first 1214 and the second 1217 batteries.

Another embodiment includes a method of using the devices of FIG. 12. The sensors 1203 are attached to the user to acquire physiological data. Exemplary sensors include those for detecting temperature, movement, electrical signals such as for an electroencephalogram or electrocardiogram, chemical sensors to measure chemical attributes of the user's physiological state such blood glucose sensors, pH sensors, blood oxygen level sensors and the like. The data acquisition is initiated and the physiological data is acquired and stored in the memory of the processor 1204 or in memory separate from the processor as discussed above but not shown here. In another embodiment the physiological data is continuously transmitted through the port 1211 to the secondary unit 1202. Data is typically acquired continuously over a long period of time perhaps extending for days, weeks or longer. The power required for the data acquisition is supplied by the batteries 1207, 1208. In one embodiment power is first supplied by the battery 1208 until it is nearly depleted. The user is then instructed through the I/O 1205 to exchange the battery 1208 with the battery 1217 contained in the secondary unit 1202. During the exchange while the battery 1208 is removed, the first unit 1201 is powered by the battery 1207. Data acquisition, processing and transmittal thereby can continue without interruption. Data acquisition can thereby also continue indefinitely with continuous exchange of batteries between the units. In another embodiment both the battery 1207 and the battery 1208 are exchangeable with the battery 1217. During use, the user is instructed via the I/O 1205 which of the two batteries to exchange with the battery 1217 of the secondary unit 1202. In another embodiment the communication 1219 between the two units includes the state of the batteries 1207, 1208 1214, 1217 and power control processor either located within the power control circuits 1215 or 1206 or included in the programs of the processors 1204 or 1213 manages charge on the four batteries so as to best provide continuous data acquisition and communication.

In one embodiment the batteries 1214, 1217 1207, 1208 are each selected to optimize ease of use. In one such exemplary selection battery 1214 is a high capacity battery and batteries 1207, 1208, 1217 are low capacity batteries. Capacity defined as the watt—hours that the battery can provide to a device when fully charged and disconnected from an external power source. The high capacity battery is located in a stationary unit 1202 and may be left at times connected to an external power supply 1218 without restriction of movement of the user. A high capacity battery has the disadvantage of being bulky and more difficult to carry around. The low capacity batteries 1207, 1208 and 1217 have the advantage of being light thus offering little restriction to the user's movements, especially during continuous operation. The disadvantage of the low capacity is overcome in the present invention by the ability to conveniently swap the battery with a charged. In one embodiment the power control circuit 1215 is controlled by a program running in the processor 1213 and the power control circuit 1206 is controlled by a program running within the processor 1204. Both power control circuits include data acquisition capabilities such as an analog to digital converter that is used to measure the voltage output of each of the four batteries 1207, 1208, 1214, 1217 such that use of the batteries is optimized to maintain continuous operation. The processors are programmed to assess the state of the batteries and to select the best source of power for operating the two devices 1201, 1202 and to alert the user to take action when required. User actions includes swapping one of batteries 1207, 1208, 1217 for one another and connecting units 1201 and 1202 to an external power supply. The program initiates action based upon the states of the batteries as shown in Table 1.

TABLE 1 Exemplary partial power control decision matrix. Charge State of battery Battery Action 1207 Battery 1208 Battery 1217 Battery 1214 No action High High High High required Swap battery Low High High High 1207 with 1217, charge the swapped battery from Battery 1214 Swap battery High Low High High 1208 with 1217, charge the swapped battery from battery 1214 Charge battery High High Low High 1217 from battery 1214 Connect unit 1202 High High High Low to external power supply to charge battery 1214 Connect both Low Low Low Low units 1201 and unit 1202 to external power supplies to maintain continuous operation and recharge batteries

In the example of Table 1 actions are take on the basis of the state of charge of the batteries. In the example shown the states are considered only high or low. In actual operation there may be intermediate states of charge.

Considering now Table 1 it is seen that if all batteries are fully charged no action is required as far as charging of batteries and no action is required of the user. If one of the batteries in the unit 1201 is low, then the user will be prompted to swap the low battery with a fully charged battery from the unit 1202. If the secondary battery 1217 in unit 1202 is low, it will be charged from battery 1214 so long as battery 1214 has a relatively high state of charge. Finally, of the examples shown in Table 1 if all batteries are low, a state that typically would be avoided, the user is prompted to connect both units to external power to maintain operation.

In one embodiment the state of charge is an estimate of the power left within the battery in terms of time that the battery could supply required power to operate the relevant device 1201, 1202 at the devices current demand. In this embodiment the power control circuit assesses the current demand for the devices 1201 and 1202. The current demand is the average current drawn by the device over time. The product of the current times time is the amp-hours draw of the device. The charge of the battery may be assessed by the output voltage of the battery which then is related to the capacity of the battery through discharge curves as are known in the art. The charge of the battery is then related to the reserve capacity of the battery through the same known discharge curves unique to each battery. The reserve capacity of the battery divided by the average current drawn by the device will give an estimate of the time that the battery will last until depletion. In another embodiment the time until depletion is added as a factor in a decision table such as that shown in Table 1 to make programmed decisions regarding actions to charge a battery and to prompt a user to swap batteries between first devices 1201 and second devices 1202, or to connect one or both devices to an external power source or all of the above.

In another embodiment the program decisions are further encoded as a function of the local time of day. It cannot be expected that the user will respond to a prompt to exchange batteries if the user is sleeping or otherwise occupied. In one embodiment the user can programmatically indicate times during the day when the user is not available to swap batteries or take other actions required of power management. Therefore, the state of charge is assessed and the program decision to swap a battery may happen at a different threshold if a long interval where it is anticipated or the user has indicated they are not available is approaching. For example, if there is a known bedtime the user may be prompted to swap batteries before that time to avoid batteries becoming depleted overnight.

In another embodiment the processor makes a continuous estimate of the operational time left for both devices with the current state of the batteries and current power demand of the devices and then selects the optimum time for the batteries to be swapped to ensure continuous operation. The estimate of the operational time includes the known times when the user is not available to take actions.

In another embodiment the swappable batteries 1208, 1217 are further associated with memory devices 1223, 1224 such that when the batteries are swapped the memory devices are also swapped. The memory devices are connected to the data acquisition module either directly or through the processor 1204 in the patch 1201 and similarly to the processor 1213 of the second device 1202. When the memory module is in the patch 1201 it is loaded with the physiological data from the sensors 1203 and when it is then swapped and placed in the second device 1202 the data is downloaded to the memory connected to the processor 1213. In this manner swapping the batteries takes care of two tasks: maintaining power and downloading the physiological data. In this embodiment the algorithm that informs to swap the batteries may use the state of charge of the batteries as discussed above or the amount of room left in the memory devices 1223, 1224. That is if memory device 1223 is near capacity and all data has been downloaded from memory device 1224 then the battery and attached memory device 1271/1224 is swapped for the battery/memory device 1208/1223. Similarly, if memory device 1224 has yet to be downloaded then swapping is postponed until the data in the memory device 1224 has been downloaded. In another embodiment the control of when to swap batteries/memory devices is made entirely on the capacity of the memory devices rather than the state of charge of the batteries. In this embodiment the batteries and paired memory devices are sized such that the batteries have sufficient capacity to more than fully load the memory device.

In another embodiment, the device 1202, further includes a link 1226 that includes inductive coupling and near field communication to the battery/memory device such that when the battery/memory device 1217/1224 is placed near the link 1226 no physical connection is required to both charge the battery 1217 as well as to download data from the memory device 1224. The battery/memory device 1217/1224 would therefore require to further include near field communication hardware, not shown.

In another embodiment shown in FIG. 13 a health care system consists of two devices 1301, 1302. The first device 1301 is intended to be a portable device to be carried and or attached to the user during continuous data acquisition. In the preferred embodiment the first device 1301 is an electrical patch as described above. The second device 1302 is intended to be a stationary device located in the vicinity of the user during data acquisition but not necessarily carried with the user through all their movements. In one embodiment the second device is only intermittently or occasionally accessed by the user during data acquisition. The first device 1301 include sensors 1303 that are attached to the user to measure a physiological parameter. Non-limiting exemplary physiological parameters are as already discussed and include ECG, EEG, blood glucose levels and others. The sensors are connected to a processor 304 that controls the data acquisition and may send the data to the second device 1302 through a communication port 1308, and may process the data and alert the user of the physiological data measurement and its significance through the user interface 1305. The user interface 1305 includes both output means to alert and inform the user as well as input means such that the user may input instructions and parameters to the processor 1304. The communication link 1317 between the first device 1301 and the second device 1302 may be wired or wireless as is known in the art and discussed earlier with respect to the system of FIG. 12. The device 1301 is powered by two batteries 1307, 1308. One or both of the batteries may be swapped with a similar battery 1315 on the second device. The first device further includes a power control circuit 1306. The power control circuit includes programmable switches controlled by either processor 1304 or a second processor (not shown) incorporated in the power control circuit 1306. The switches control whether the device 1301 is powered solely from the first battery 1307, the second battery 1309 or both batteries. The power control circuit may be programmed to switch between the first battery, the second battery and/or both based upon a measured state of charge of the two batteries. The switching between batteries is done to maintain continuous data acquisition operation. The processor also indicates to the user that one of the batteries should be swapped with the battery 1315 contained in the second unit. In one embodiment the communication link 1317 includes information regarding the state of charge of all batteries of the system 1307, 1309, 1312, 1315 such that the processor can therefore select only to swap a discharged battery with a charged battery. Thus avoiding the fruitless swap for instance of a discharged battery in the first unit 1301 with a similarly discharged battery in the second unit 1302. Note a feature missing from the first device 1301 is a connector to an external power supply. Unlike the device described in conjunction with FIG. 12 all power for the device is obtained from the batteries 1307, 1309. The second device of the embodiment of FIG. 3 is similar to the device 1217 discussed in conjunction with FIG. 12. The second device 1302 consists of a communication port 1311 that is linked 1317 to the first device and also linked 1318 to remote users through a connection 1319 that is one selected from a local network or a global network. Either network may be connected through wired or wireless means as are known in the art and already discussed. The second device 1302 further consists of a processor 1310, a power control circuit 1316 two batteries 1312, 1315. The second battery 1315 sized such that it may be swapped with a like battery on the first device 1301. The device 1302 also includes a port 1313 for connection to an external power supply 1314. In one embodiment the first battery 1312 has a higher capacity than the second battery 1315 and can be used to charge the second battery even when the second device 1302 is not connected to an external power supply.

In another embodiment the power supply circuit 1316 in conjunction with the processor 1310 is used to control the charge of the first battery 1312 and the second battery 1315 on the basis of the state of charge of the two batteries to maintain continuous operation of both device 1 and device 2. In another embodiment the communication link 1317 includes communication of the state of charge for all batteries 1307, 1309, 1312, 1315 and the user is prompted via the input output interface 1305 to swap either one or both of batteries 1307, 1309 with battery 1315 to maintain operation of the device 1301 for continuous measurement of physiological data. In another embodiment the user is also prompted to connect the device 1302 to an external power supply 1314.

In another embodiment shown in FIG. 14, a health care data system including battery management includes two devices 1401 and 1402. The first device is comprised of sensors 1403 to be attached to the user to acquire physiological data, a processor 1404, an input/output device 1405, a power control circuit 1406 and communication port 1407 that is linked 1408 to the second device 1402, a battery 1409 and a temporary source of power 1419. The temporary source of power is used to power the device 1401 when the battery 1409 is not present as would be the case while it is being swapped with the battery 1415 of the second device 1402. In a preferred embodiment the second device 1402 is an electrical patch for acquiring physiological data as described in FIGS. 2-11. Nonlimiting examples of the device 1419 include a low capacity battery and a capacitor. The second device 1402 is comprised of a processor 1410, a communication port 1411, a first battery 1412, a power connector 1413 that can be connected to an external power supply 1414, a second battery 1415 that is sized such that it can be exchanged with the battery 1409 of the first device and a power control circuit 1416. The communication port 1411 has a communication link 1408 to the first device 1401 and a communication link 1417 to space external to the user 1418. The external connection may be to a local network, the internet or to a cellular network. The external connection allows communication of the physiological data and results of analysis of the physiological data to others such as a care giver, technician, or coach. In one embodiment the communication link 1408 to the first device includes communication of the state of charge of the batteries 1412,1415, 1409 and device 1419 to both processors 1410, 1404. In this embodiment the processors 1404, 1410 work in conjunction to maintain a charges for continuous operation through control of the charging through the power control circuits 1406, 1416. In the embodiment of FIG. 4 all communication to the user and user input is through the I/O means 1405. There is no I/O means for user interaction on the second device 1402.

Referring now to FIG. 15, an additional block diagram view of the electrical components of embodiments of the invention are shown. The health care device is seen to be comprised of two main component devices 1501, 1502. The first device 1501 is intended to be worn on the person of an ambulatory user and the second device 1502 is intended to be stationary but available for at least occasional access by the user. The first device 1501 is comprised of sensors 1503 that are connected to the user to gather physiological data. In a preferred embodiment the first device is an electrical patch as described in FIGS. 2-11. The sensors are connected to a processor 1504 that is used to acquire and optionally process and transmit the data to the second device 1502. Also connected to the processor are an I/O component 1511 for interaction with the user and an I/O port 1512 for communication with the second device. The first device is further comprised of two batteries 1505, 1506. Either one or both of the batteries may be swapped with the battery 1517 of the second device. Also included is a power control circuit 1507. The power control circuit consists primarily of switches that are controlled by the processor 1504. The switches allow the device to be powered by the first battery 1505, the second battery 1506 or both. The resistive component 1508 represents the load for operating the second device. The analog to digital converters 1509, 1510 allow the processor 1504 to assess the state of charge of the batteries. The second device 1502 is comprised of a processor 1513 and a power control circuit 1514. The power control circuit includes a switch 1515 that can interconnect the devices 1516, 1515, 1519, 1520 connected to the switch under control of the processor 1513. The power circuit 1514 further includes a power supply 1519 that provides power to the device from an external power supply 1518. In the case that the external power supply 1518 is not compatible with the requirements of the device the power supply 1519 can convert and AC source to DC and step up or down the voltage to the required level. The power control circuit 1520 further includes a second transformer that is selected such that the input voltage of the power source connected through the switch is suitable for charging the battery 1517. The battery 1517 can be swapped with one or both of the batteries 1505, 1506 of the first device. The second device further includes a first battery 1516 that is used to power the device when it is not connected to an external power supply 1518. The state of charge of the battery 1517 is measured using an A/D converter 1521 that is connected to the processor 1513. Similarly, the state of charge of the battery 1516 is monitored through the A/D converter 1522. The second device 1502 further includes an I/O component 1524 for interacting with the user and an I/O port 1523 for communicating with the first device 1501 as well as transmitting measured physiological data and/or results of assessment of physiological data to a remote site. In one embodiment the I/O component 1524 is not present and all interaction between the two devices and the user takes place through the I/O component 1511. The resistive element 1525 represents the power load of the second device 1502.

In another embodiment the method of using the health care device of FIG. 5 includes monitoring the estate of charge of the batteries 1505, 1506, 1516, 1517 and using pre-selected parameters select between the connections through switches 1507, 1515 under operational control of the processors 1504 and 1513. In a typical operation scenario, the collection of physiological data is begun by attaching sensors 1503 to the user and initiating operation through the I/O component 1511. Power to acquire the physiological data is provided by battery 1505. The processor monitors the state of charge of the battery 1505 and when the state of charge falls below a pre-selected level the switch 1507 is activated to provide power from battery 1506. The user is then prompted through the I/O component 1511 to switch the no depleted battery with the battery 1517 of the second device. Where it would be recharged. Thereby providing a fresh source of power for continuous operation. Simultaneous to the operation of the first device 1501, operation of the second device is also initiated. The power to operate the device can be provided by an external power supply 1518 or the internal battery 1516 or if required, both. Switching between the power supplies is controlled by the power control circuit 1514 through the switching element 1515 under control of the processor 1513. The state of charge of the batteries 1516 and 1517 is monitored continuously. If the state of charge of the battery 1517 is below a pre-selected level, then the switch 1515 is activated to connect the battery to a source of power for recharging. Charging is continued until the state of charge returns to a pre-selected “fully charged” level. In one embodiment the user is informed of the state of charge of the battery through the I/O component 1524. In another embodiment the user is informed of the state of charge of the battery through the I/O component 1511 on the first device 1501. In the latter embodiment the state of charge of the battery is transmitted from the processor 1513 of the second device to the processor 1504 of the first device through the I/O ports 1523, 1512. If during continuous monitoring of the state of charge of the battery 1516 the state of charge falls below a pre-selected level the user is prompted to connect the second device 1502 to an external power supply 1518. Note that when not connected to an external power supply charging of the battery 1517 may take place from power supplied by battery 1516.

Referring to FIG. 16, a flow chart of a method of using the invented embodiments is shown. The user initiates 1601 acquisition of physiological data. The system then begins continuous monitoring of the state of charge of the batteries 1602. The state of charge is tested against a pre-selected level and a decision is made 1603 as to whether charging (or stop charging is required if charging is already taking place). If no action is required (the “NO” path) assessment of the batteries is continued during operation. If it is found that that the battery charge level is below (or above) pre-selected levels. Then a decision is made 1604 as to whether user intervention is required and if so what is required. The criteria for the decision 1604 is pre-programmed in the processor of the first device or the second device or both. Exemplary programmed criteria include:

-   -   1. If state of charge of first battery of the second device is         below a pre-selected level AND the device is not connected to an         external power supply, then user intervention is required and         the proscribed user intervention is to connect the second device         to an external power supply.     -   2. If the state of charge of the first battery of the second         device is below a pre-selected level AND the device is connected         to an external power supply, then user intervention is not         required.     -   3. If the state of charge of one of the batteries in the first         (portable) device is below a pre-selected level (discharged) and         the state of charge of the swappable battery in the second         device is above a pre-selected level (indicating a full charge)         then user intervention is required and the proscribed         intervention is to swap the discharged battery of the first         device with the fully charged battery of the second device.

If user intervention is required (the YES path off 1604) the user is prompted 1605 the subsequent action based upon user intervention 1606 is taken. Subsequent action implies that action appropriate for the defined user intervention. If for example the user intervention is to connect one or both of the devices to an external power supply the subsequent action 1606 would be to control the power control circuit to supply power to the device from the now connected external supply. If the user intervention is to swap a battery between the first device and the second device the subsequent action 1606 would include charging the discharged battery. If user intervention is not required (the NO path off 1604) action 1607 is taken based upon pre-selected program steps. Exemplary actions include: starting or stopping charging of a particular battery(s), switching to external power from battery power, switching from use of one battery for power to the second battery for power. Once action 1607 is complete processing continues back to assessing 1602 the state of the batteries. In another embodiment the assessment 1602 is based upon capacity of a swappable memory device and the user intervention includes swapping the memory device along with the battery. The action would be consistent with the device of a paired battery/memory device as described in FIG. 12 above.

Mirroring Algorithm

The patch acquires a physiological signal from sensor(s) and provide initial preprocessing of the data acquired. However, the patch has limited computational resources and small amount of memory. As a result, preprocessing algorithms running on a patch prior art devices have been unchangeable once the device is attached to the user. Prior art devices also have a limited adaptation mechanism to “personalize” particular physiological (e.g. specific heart arrhythmia) and environmental (e.g. electronic noise) differences. To resolve this issue, the patch of the instant invention uses a procedure to “mirror” the algorithm running on the patch to the algorithm running on a server. While the algorithm running a server has the same logic, it also has access to all data acquired before, and all correct labels for these data. The server performs the computationally (and energy) intense operation of perform adaptation (learning) to determine optimal algorithms for analysis, filtering and compression of the acquired data and acquisition parameters. Once the server side algorithm was adapted to fit a particular person/data acquisition scenario, the server determined algorithms and parameters are uploaded to the algorithm residing on a wearable device. Since both algorithms (server side and wearable side) have the same execution logic, then the wearable device will show improvement in performance in accordance with optimization done on a server. The server runs optimization schemes that select optimized parameters for data acquisition, filtering and compression. The optimized algorithms and parameters are then loaded onto the patch. Optimization significantly reduces the data acquisition and data transfer burdens on the algorithms running on the patch thereby decreasing memory requirements on the patch and reducing the amount of data required to be transferred. Data transfer through RF communication is one of the significant power usages on the patch. Optimizing data structure through filtering and compression can reduce this burden therefore enabling a patch that has smaller battery requirements and can last longer in standalone data acquisition. The mirroring process is shown in FIG. 17. A data acquisition process is initiated 1701 by loading a default set of data acquisition, filtering and analysis algorithms from a server 1703 onto the microprocessor included in the patch. In a preferred embodiment the data acquisition parameters include collecting raw data from the patch and transferring the raw data to the server either directly or through an intermediate communication device. Data is acquired 1702 by the patch and transferred to the server. The transfer may take place by any of the means already discussed. The server 1703 analyses 1709 the raw data using the same algorithm as the default algorithm that was transferred to the patch. The server and the microprocessor on the match are mirrors of one another as far as data analysis is concerned. The server can then further analyze the data using additional algorithms. In one embodiment the server selects an alternative algorithm and parameters looking or accuracy of a particular diagnostic test. In another embodiment the server looks for optimum data acquisition and analysis algorithms with the goal of minimizing the energy required by the patch. In parallel the patch processes 1704 the acquired data using the default parameters initially installed at the first step 1701. The patch enters a loop 1705-1708 of data acquisition and analysis and in some embodiments diagnosis 1707. The decision step 1708 looks for a signal from the server that the new optimized parameters/algorithms should be installed on the patch. If so indicated, updated parameters/algorithms are installed and data acquisition and analysis 1705, 1706 continues with the updated parameters/algorithms. The process step 1706 includes uploading data to the server for further analysis and optimization 1709. The frequency and nature of the data uploaded to the server is determined by the parameters downloaded to the patch from the server at either the initial step 1701 or the later downloaded optimized parameters at the decision/interrupt step 1708. The process continues with the patch continuously acquiring and analyzing the data in steps 1705-1708 and the server periodically receiving data from the path at step 1706 and determining if the parameters/algorithms should be updated. The physical location and the timing of the data acquisition and analysis loop 1705-1708 depends upon the particular hardware configuration of the patch as discussed in FIGS. 7-11. As an example if the patch is one of minimal configuration as shown in FIG. 7, the patch may only acquire and store data to a memory device and further analysis is done either on a local intermediate communication device or on the server itself. If the patch's hardware configuration is as that shown in FIG. 11, then all of the acquisition and analysis steps 1705-1708 may be done on the patch itself. Intermediate configurations as shown in FIGS. 8-10, will assign some tasks to the microprocessor on the patch and others to either the server or an intermediate communication device. In one embodiment the physical device where the steps are performed is determined in the optimization step 1709. In one embodiment the decision and update step 1708 includes installing new algorithms on the patch. In another embodiment the step 1708 includes only directing the patch to use a different set of parameters and algorithms that are already contained in memory on the patch. In this latter embodiment the patch and the server may each include a library of parameter settings and algorithms mirrored on each device and optimization includes selecting the best set to use for the particular physiological data acquisition scenario. The update then needs to simply point the microprocessor to the optimized selected set of parameters and algorithms that are already installed on the patch. Such a system minimizes the data transfer requirements form the server to the patch while maintaining the flexibility to update and optimize data acquisition and analysis settings. In another configuration the algorithms and parameters are downloaded to the patch and the patch then needs minimal memory for algorithm storage.

In one example embodiment of mirroring algorithms are used for arrhythmia detection algorithms. In another embodiment, parameters for the algorithm run on the patch are mirrored. Without the loss of generality, in one implementation of mirroring scheme for an AFIB detection algorithm, it is known that during AFIB episodes the Heart Rate variability is much higher than in a normal sinus rhythm. Therefore, we detect AFIB episodes just by measuring R-R standard deviation:

AFIB on condition: Stdev(RR)>threshold AFIB off condition: STdev(RR)<threshold

Where “threshold” is a parameter that is set to 200 ms as an initial value. For some patients who exhibit high numbers of premature Atrial contractions (PACs), this threshold of R-R variability might be too low, and this algorithm will trigger a lot of false positive AFIB events. In the process of FIG. 17, the server will process data (step 1706) and will determine the optimal “threshold” parameter. If, for example this patient's normal sinus rhythm with PACs will be rejected if threshold is set at 274 ms or higher. Then, during the optimization step 1709, the server will determine that the best sensitivity and specificity will be achieved with the threshold of 274 ms. Then, server will send a new threshold parameter back to the algorithm (step 1708). This new threshold parameter will be an optimal value for this particular patient. While processing algorithm remains the same, optimal parameter setting for the patient will result in much more specific AFIB triggers.

In another embodiment mirroring includes using a more sophisticated AFIB detection algorithm, which also has parameter setting responsible for different values of sensitivity/specificity. Studies have shown that there are different optimized parameter values corresponding to a different patients. Setting this parameter to an optimal value can be critical to achieve best algorithm performance. Therefore, the embodiments of FIG. 17 of optimization of parameters on a server, and then mirroring the algorithm and thresholds on a patch provides high detection of heartbeat anomalies while at the same time minimizing false positives.

SUMMARY

An electrical patch and associated system for acquisition of physiological data is described. The patch has a design that enables a variety of configurations depending upon the requirements physiological measurements to be made. Patches with single input channels to patches with multiple input channels, processing capabilities and radio communication can all use the same physical configuration. The design includes a battery management system to enable long term data acquisition and an optimization process that includes mirroring of algorithms on the patch and devices local to the user with algorithms running on a centrally located server. The server can then optimize data acquisition and analysis algorithms. The components of the system and methods of use are included.

Embodiments of the physical configuration of the electrical patch was described in FIG. 1-6. Configurations included various microprocessor, memory and radio communication capabilities. The patch was described to include a printed circuit board that includes a microprocessor, an input port, an analog to digital converter, a power supply, a first battery, and, computer memory, said printed circuit board attached to a base made from compressible and breathable material. The patch included a plurality of electrodes connected to articulated arms of the printed circuit board and the electrodes connected electrically to the input port, the electrodes having a thickness, and extending through and a distance beyond the base. The patch is enclosed in a clamshell cover having a bottom, attached to the base, and a top, attached to the bottom, and, thereby encasing the printed circuit board. The microprocessor is programmed to receive and electrical signal from the electrodes and store data that includes values for the electrical signal in the memory.

Different embodiments of attachment of the electrodes were shown at least in FIGS. 5 and 6. In some embodiments the electrodes are secured to the bottom of the clamshell cover. In some embodiments the printed circuit board is removable. This allows the patch electrodes to remain attached to the user while the electronics may be changed or the unit moved to a separate computing device or data transfer. In one embodiment the printed circuit board is attached to the top of the clamshell cover.

For comfort, hygiene and long term use some embodiments of the patch included a base impregnated with wound dressing material. Improvements in the patch design include the use of dry electrodes composed of a conductive metal and including electrodes sputter coated with TiN, and electrodes made of a polymer base that is coated with a conductive metal. FIGS. 7-11 described electrical component variations. Embodiments of the patch include an accelerometer, said accelerometer electrically connected to the microprocessor and controlled by the microprocessor, and said microprocessor, upon receiving a signal from the accelerometer, programmed to determine the position of the user based upon the signal from the accelerometer. Other embodiments include a global positioning device, said global positioning device connected to and sending a signal to the microprocessor and said microprocessor programmed to determine a physical location of the user based upon the signal from the global positioning device. Embodiments include various means to transfer the data collected in the memory of the patch to an external computing device. In one the memory of the patch is removable. In others a radio transmits data. FIGS. 12-16 describe embodiments that include a battery management system.

In FIG. 17 embodiments of the patch that include analysis of the collected data and mirroring of algorithms between the microprocessor on the patch and an external computing device were described. Embodiments also include an electrical patch wherein the external computing device is further programmed to select an optimum algorithm for analyzing the stored data, and, when selected, to transfer the selected optimum algorithm to the microprocessor on the patch and the patch is thereby reprogrammed to analyze the stored data using the selected optimum algorithm.

Those skilled in the art will appreciate that various adaptations and modifications of the preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that the invention may be practiced other than as specifically described herein, within the scope of the appended claims. 

What is claimed is:
 1. An electrical patch for physiological measurements of a user, said patch comprising: a) a printed circuit board that includes a microprocessor, an input port, an analog to digital converter, a power supply, a first battery, and, computer memory, said printed circuit board attached to a base made from compressible and breathable material, the base having a thickness, b) a plurality of electrodes connected to articulated arms of the printed circuit board and the electrodes connected electrically to the input port, the electrodes having a thickness, and extending through and a distance beyond the base, c) a clamshell cover having a bottom, attached to the base, and a top, attached to the bottom, and, thereby encasing the printed circuit board, and, d) wherein the microprocessor is programmed to receive and electrical signal from the electrodes and store data that includes values for the electrical signal in the memory.
 2. The electrical patch of claim 1 wherein the electrodes are secured to the bottom of the clamshell cover.
 3. The electrical patch of claim 1 wherein the printed circuit board is attached to the top of the clamshell cover.
 4. The electrical patch of claim 2 wherein the printed circuit board is attached to the top of the clamshell cover and further including a connector between the printed circuit board and the electrodes such that the top of the clamshell may be removed from the bottom of the clamshell and the printed circuit board is thereby disconnected from the electrodes.
 5. The electrical patch of claim 1 wherein the base is impregnated with wound dressing material.
 6. The electrical patch of claim 1 wherein the electrodes are dry electrodes composed of a conductive metal.
 7. The electrical patch of claim 6 wherein the electrodes are sputter coated with TiN.
 8. The electrical patch of claim 1 wherein the electrodes are made of a polymer base that is coated with a conductive metal.
 9. The electrical patch of claim 1 wherein the base is removable and interchange with bases having a different thickness.
 10. The electrical patch of claim 1 further including a battery management system said battery management system comprising: a) a second device deriving its power from a second battery, physically separate from the electrical patch, and electronically linked to the electrical patch, said second battery of a same size and type as the first battery, b) a battery charger associated with the second device wherein the battery charger is connected to an energy source that can be used to charge the second battery, c) a monitor for the state of charge of the first battery and the second battery, and said monitor having a signal to signal the user to swap the first and second batteries when the state of charge of the first battery is below a pre-selected level, and when the state of charge of the second battery is above a preselected level.
 11. The electrical patch of claim 1 further including an accelerometer, said accelerometer electrically connected to the microprocessor and controlled by the microprocessor, and said microprocessor, upon receiving a signal from the accelerometer, programmed to determine the position of the user based upon the signal from the accelerometer.
 12. The electrical patch of claim 1 further including a global positioning device, said global positioning device connected to and sending a signal to the microprocessor and said microprocessor programmed to determine a physical location of the user based upon the signal from the global positioning device.
 13. The electrical patch of claim 1 wherein the memory is removable, and, the stored data in the memory is transferred to a computing device that is located separate from the electrical patch by physically removing the memory from the patch and attaching the memory to the computing device.
 14. The electrical patch of claim 13 further including a radio device on the printed circuit board, said radio device electrically connected to and controlled by the microprocessor, and, the stored data in the memory is transferred to a computing device that is located separate from the electrical patch by a radio connection from the electrical patch to the computing device.
 15. The electrical patch of claim 14, wherein the microprocessor is programmed to include an algorithm to analyze the stored data and if the results of the algorithm's analysis is outside of preselected limits to send a signal to computing device located separate from the electrical patch, and, the computing device also programmed to analyze the stored data received from the electrical patch using the same algorithm.
 16. The electrical patch of claim 15 wherein the computing device is further programmed to select an optimum algorithm for analyzing the stored data, and, when selected, to transfer the selected optimum algorithm to the microprocessor on the patch and the patch is thereby reprogrammed to analyze the stored data using the selected optimum algorithm. 